20,000 posts: MILF - 19,145 - Peeg just too intermittent.
16,000 posts: Rantz - 15,274 - although GoBo's statement of intent could certainly make this interesting.
14,000 posts: Neo - 13,350 - this was very hard to call as none of them are massively prolific, but rather steady-does-it types.
11,000 posts: Chris - 10,549 - Chris vs. Pike for this one, I don't think Laddy will keep up (although he could surprise). I think Chris's lead on Pike and his high posting activity recently will lead him to getting it.
10,000 posts: DMKA - 9,982 - just, although him slowing even just a little could mean Sarah or Sam snatching it. I think of those two, Sarah's lead is juuust too much for Sam.
8,000 posts: Big D - 7,980 - 6 posts so far this month, I think he can manage another 20 before the others catch up. Iceglow is oddly not a bad shout, Vivi22 and Ouch! also good contenders.
7,000 posts: Sephex - 6,627 - He's got too big a lead for Phil to catch up and he posts more than anyone on the list.
5,000 posts: Faris - 4,945 - Just too close, although Pimp is genuinely an interesting shout as competition given what's coming up. I don't think he'll have enough reason to catch up and I think Faris will hit 5,000 in the Ciddies thread if it's that active anyway.
4,000 posts: IDNAN - 3,975 - Again, just too close for Locky to catch up unless he stops posting suddenly.
2,000 posts: shion - 1,828 - She's easily gonna beat those listead above her at the moment on her current post rate, and although noxious is insane for postcount lately, I don't think she can manage over 1,000 before shion gets another 172.
750 posts: Flaming Ice - 500 - Bottom of the list but easily most active.
500 posts: Scotty_ffgamer - 324 - Again bottom of the list, but I've got a feeling he'll steal it due to how slowly the others post.
300 posts: DanielCLFFF13 - 282 - Any of these could get it, but I'm thinking Daniel will manage it. Yeru a good outside bet.
250 posts: LadyJuxtaposition - 244 - She only needs six posts, I'm sure she'll do it. Still, there's not a lot in this one.
200 posts: LocoColt04 - 146 - LFC, comma and Mr. Shauna could get it, but I think Loco is posting at a decent speed and will get there first.
100 posts: Bierhumpen_Kukki - 56 - Snakz92 or Kukki for me. The others won't post again anytime soon, I think. Xannidel might sneak back and walk it, though, you never know...

EDIT: Probably worth noting that staff may have a slight advantage in this should some massive staff discussion come up, but it's not been too active there lately so I think many non-staffers can easily compete.